THE BUSHVELD COMPLEX:

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D.I. Groves, June 2003
THE BUSHVELD COMPLEX DYNAMIC PROCESSES AT ALL
SCALES

• Static vs Dynamic Models
• Bushveld Complex Settings
• Basin Analogy Model
• Potholes in Merensky Reef
• and UG 2
• Magma / Fluid Fluxes
• Large Scale Magma Flux
• Perspective

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STATIC VS DYNAMIC MODELS
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Introduction to Southern Africa
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METALLIC MINERAL RESOURCES ( Mined and Potential)
IN SOUTHERN AFRICA
World Leader (alphabetical order) Significant
Producer Chromium Great Dyke, Bushveld
Antimony Murchison Gold Witwatersrand
Copper Various, e.g. OKiep, Zimbabwe Phalabo
wra Manganese Griqualand West etc.
Lead Various, e.g. Gamsberg,
Tsumeb Platinum Bushveld,
Nickel Bushveld, Trojan, Great Dyke
Pikwe Titanium Bushveld, Natal Coast Rare
Metals Bikita Uranium Witwatersrand,
Zinc Various, e.g. Namibia Gamsberg,
Vanadium Bushveld Black Mountain Zirconium Na
tal Coast
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EXTENT OF BUSHVELD COMPLEX
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BASIN ANALOGY MODEL FOR BUSHVELD
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So
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Normal Reef Abnormal Geologist
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Merensky Reef
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POTHOLES vs NORMAL REEF
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HOT SHEAR DVAARS RIVER CHROMITITES
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COMPLEX UG 2 REEF
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POTHOLE IN UG 2 REEF
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POTHOLE IN MERENSKY REEF UNDERGROUND
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EXTENSIONAL SANDBOX - MODEL
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NEPTUNIAN DYKE OF MERENSKY REEF UNDERGROUND
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GIS SYNTHESIS OF DIP OF HANGING WALL OF MERENSKY
REEF
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OTHER EVIDENCE OF FLUID MAGMA FLUX
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EVIDENCE OF REPLACEMENT OF ANORTHOSITE
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FURTHER EVIDENCE OF INTRUSION OF RESIDUAL MELTS
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DUNITE PIPE
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Platreef
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Explanation in Progress
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Drilling in the Suburbs
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EXTENT OF BUSHVELD COMPLEX
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SOME POINTS FOR DISCUSSION

• Where is the feeder zone (or zones) ?
• Is the Platreef unique ? What has happened to
  the north ?
• Is there value in mapping out the areas of
  greater disturbance
• more dynamic zones in the Bushveld Complex
  ?
• Are there potentially other deposit styles
  (e.g. Ni-Cu) ?
• Are there, as yet undiscovered, more dynamic
  zones in the
• Great Dyke of Zimbabwe ?
• Is there potential for a Platreef in other
  layered intrusions
• (e.g. Stillwater) ?